# OS_DisableIrqMask

## C Specification

  `#include <nitro/os.h>`
  `OSIrqMask OS_DisableIrqMask( OSIrqMask intr );`

## Description

Sets the IRQ interrupt cause

In addition to the current setting, the designated cause's enable bit is disabled. Refer to `OS_SetIrqMask` for a description of each cause and its corresponding value.

## Internal Operation

Operates on one of the IO registers, IE (Interrupt Enable).

## Arguments

`intr` | The IRQ interrupt cause to be prohibited (expressed as a logical sum)

## Return Value

This is the IRQ interrupt cause that was set before this function is called.

## See Also

`OS_EnableIrqMask`, `OS_SetIrqMask`

## Revision History

12/01/2003 Initial version